/*
 * JBoss, Home of Professional Open Source
 * Copyright 2010, Red Hat, Inc. and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jdiameter.server.impl;

import org.jdiameter.api.Avp;
import org.jdiameter.api.AvpSet;
import org.jdiameter.api.ResultCode;
import org.jdiameter.client.api.IMessage;

/**
 * This class provides check incoming/outgoing diameter messages.
 * Check's rules consist into xml file.
 * 
 * @author <a href="mailto:brainslog@gmail.com"> Alexandre Mendonca </a>
 * @author <a href="mailto:baranowb@gmail.com"> Bartosz Baranowski </a>
 */
public class MessageValidator {

    public static final Result SUCCESS = new Result(null, ResultCode.SUCCESS);

    private boolean enable = true;

    public MessageValidator() {
        // todo load validator rules
    }

    /**
     * Enable validation functions
     */
    public void enable() {
        enable = true;
    }

    /**
     * Disable validation functions
     */
    public void disable() {
        enable = false;
    }

    /**
     * Return true if validation function is on
     * @return true if validation function is on
     */
    public boolean isEnable() {
        return enable;
    }

    /**
     * Validate message
     * @param message message instance
     * @return result of validation procedure
     */
    public Result check(IMessage message) {
        if (message == null)
            throw new IllegalArgumentException("Message is null");
        if (!enable)
            return SUCCESS;
        // todo
        return null;
    }

    public static class Result {

        private IMessage errorMessage;
        private long code = ResultCode.SUCCESS;

        Result(IMessage errorMessage, long code) {
            this.errorMessage = errorMessage;
            this.code = code;
        }

        /**
         * Return true if message is correct
         * @return true if message is correct
         */
        public boolean isOK() {
            return code == ResultCode.SUCCESS || code == ResultCode.LIMITED_SUCCESS;
        }

        /**
         * Return long value of result code
         * @return long value of result code
         */
        public long toLong() {
            return code;
        }

        /**
         * Create error answer message with Result-Code Avp
         * @return error answer message
         */
        public IMessage toMessage() {
            if ( errorMessage != null && errorMessage.getAvps().getAvp(Avp.RESULT_CODE) == null )
                errorMessage.getAvps().addAvp(Avp.RESULT_CODE, code);
            return errorMessage;
        }

        /**
         * Create error answer message with Experemental-Result-Code Avp
         * @param vendorId vendor id
         * @return error answer message with Experemental-Result-Code Avp
         */
        public IMessage toMessage(int vendorId) {
            if ( errorMessage != null && errorMessage.getAvps().getAvp(297) == null ) { // EXPERIMENTAL_RESULT = 297
                AvpSet er = errorMessage.getAvps().addGroupedAvp(297);
                er.addAvp(Avp.VENDOR_ID, vendorId);
                er.addAvp(Avp.EXPERIMENTAL_RESULT_CODE, code);
            }
            return errorMessage;
        }
    }
}
